How to configure a user's fair share of the pool

To see the current priorities and priority factors for users, use the following command:

condor_userprio -all -allusers

To configure things so that user A can use 2x the number of machines as user B based on their user priorities, set user B's priority factor to be 4 times that of user A. Example:

condor_userprio -setfactor B 4.0
condor_userprio -setfactor A 1.0

Why should the priority factor be 4 times instead of 2 times? Recall that effective priority is the real priority times the priority factor. A user's fair share of the pool is inversely proportional to their effective priority. A user's real priority over time tends towards the number of machines they have been using recently. Working backwards... At steady state, A's real user priority will be 2x that of user B, because A will be using 2x the number of machines on average. But we want B's effective priority to be 2x user A's, because that is what will allow A to be claiming 2x the number of machines as B. This gives the following equations:

Note that if your pool uses startd RANK to give some users/jobs high priority on some machines, adjusting the user priority will only have an effect when two users with equal startd RANK are competing. This is because a match with a higher startd RANK will preempt a match with a lower startd RANK, even if the latter has a higher user priority.

This work supported in part by NSF grants MCS-8105904, OCI-0437810, OCI-0850745, and/or ACI-1321762. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. Site built using CVSTrac.